Walkom worked referee, until retiring August 3 2005 when he elevated to the management position. Walkom succeeded Andy Van Hellemond as director of officiating, who resigned under controversy in mid-July 2004.

He was also the director and owner of the North American School of Officiating, a summer development camp for aspiring hockey officials in Guelph, Ontario, Canada. [2]

The Sports Businnes Journal released Walkom's annual salary in July, 2010, to be US$488,736 per year.

On August 25, 2009 he announced his decision to step-down from his position as the NHL's Director of Officiating to allow him to attempt a comeback at on-ice officiating as a referee. His first game back as an NHL Referee was October 21, 2009 when Florida hosted Buffalo.